Shaw attacked the national government for its ‘woefully inadequate’ target of an 11% cut to emissions below 1990 levels by 2030. The goal was set ahead of a major UN climate change conference later this year.

In a speech at the Victoria University law school in Wellington Shaw detailed three proposals in a ‘Yes we can’ discussion paper released on 3 September. The party re-iterated a policy to scrap the emissions trading scheme (ETS) and replace it with a carbon tax on industry polluters of NZ$25 (£10) per tonne. This price would ‘significantly increase’ over time.

Farmers – who are exempt from the ETS – would pay a reduced rate of NZ$12.50 – but the Greens are now mooting a five-year grace period before farmers are liable for the tax.